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January 30, 2011

Types of Vaccines

There are several types of vaccines that are designed to trigger the body to produces an immune response. Vaccines are made differently depending on the characteristics of the disease infecting agent, whether it is a bacteria, virus or toxin. There are two main types of vaccines 1) Live, attenuated vaccines and 2) inactivated vaccines.

Live attenuated vaccines

Live attenuated vacines are made up of living virus or bacteria that have been modified through a process to weaken (attenuate) and reduce it's virulence (disease inducing ability). These wild viruses or bacteria are attenuated in a laboratory, usually by repeated culturing. For example, the measles vaccine used today was isolated from a child with measles disease in 1954. Almost 10 years of serial passage on tissue culture media was required to transform the wild virus into vaccine virus . A live attenuated vaccine creates a good immune response (cellular and antibody) and often provides lifelong immunity with only one or two doses. Certain vaccines against viral diseases are made this way, eg measles, mumps, and chickenpox. Because these vaccines are live, they are contraindicated for people with impaired immunity; for example people suffering from leukaemia or HIV infection.

Inactivated vaccines

Inactivated vaccines do not contain live virus or bacteria. The diseases microbes have been killed by chemicals, heat or radiation. They cannot replicate and cause disease. Inactivated vaccines stimulate a weaker immune response than live vaccines and always require several doses to provide a pretective immmune response. Immunity can also diminish over time and a booster shot is required to maintain immunity. Inactivated vaccines can be composed of either whole viruses or bacteria, or fractions of either

Subunit vaccines

These vaccines don't use the entire microbe, but instead are made from only part of the microbe. Scientist use the 'part' that best stimulates the immune system. Because these vaccines only use a part and not all the other molecules that make up the microbe, the chances of adverse reactions to the vaccine are lower.

Conjugate

These vaccines are very important especially in young infants. Some bacteria that can cause disease have a special outer coating (sugar molecules called polysaccharides) that hides them from the immune system (especially immature immune system of infants).Conjugate vaccines link these coatings to an antigen or toxiod that an immature immune system can recognize, so it can respond and produce immunity. The linkage helps the immature immune system react to polysaccharide coatings and defend against the disease-causing bacterium.Examples of conjugate vaccines are Haemophilus influenzae type B (Hib)vaccine, pneumococcal vaccine and meningococcal vaccines in which a non toxic tetanus toxiod or non toxic diptheria protein is used as the link to stimute the immune system.

Toxiod vaccine

When the cause of an illness is the bacteria releasing a toxin (harmful chemical) that affects the body, a toxiod vaccine can provide protection. Scientists formulate a vaccine from just the deactivated toxin (called toxiod), rather than the whole bacteria. A toxin can be inactivated by treating them with formalin, a solution of formaldehyde and sterilized water. Toxiods are safe for use in vaccines and the immune system produces antibodies that lock onto and block the toxin. Vaccines against diphtheria and tetanus are examples of toxoid vaccines.

Recombinant vector vaccines

Vaccine antigens may also be produced by genetic engineering technology. Hepatitis B and Human Papillomavirus (HPV) vaccine ( vacine to proterct against cervical cancer) is developed this way.

January 27, 2011

A measure of absolute poverty quantifies the number of people below a fixed real poverty threshold. Absolute poverty is a level of poverty at which certain minimum standards of living -- for example for nutrition, health and shelter -- cannot be met.

Relative poverty is a poverty measure based on a poor standard of living or a low income relative to the rest of society. Unlike absolute poverty, it does not necessarily imply that physical human necessities of nutrition, health and shelter cannot be met; instead it suggests that the lack of access to many of the goods and services expected by the rest of the contemporary society leads to social exclusion and damaging results for the individuals and families in relative poverty. Measurements of relative poverty are similar to measurements of social inequality

There is a distinction between absolute poverty indices and relative poverty indices. Relative poverty indices are also known as inequality indices. Poverty line is thus measured in terms of absolute poverty. Absolute poverty line can be lower than the lowest income and higher than the highest income.

Relative poverty deals with the socio-economic status of an area. However, absolute poverty is some who is destitute.

January 25, 2011

Expert Group Methodology – Lakdawala Committee The Lakdawala Committee defined the poverty line based on per capita consumption expenditure as the criterion to determine the persons living below poverty line. The per capita consumption norm was fixed at Rs.49.09 per month in the rural areas and Rs.56.64 per month in the urban areas at 1973-74 prices at national level, corresponding to a basket of goods and services anchored in a norm of per capita daily calorie intake of 2400 kcal in the rural areas and 2100 kcal in the urban areas. The Expert Group disaggregated the National Poverty lines separately in rural and urban areas into States specific poverty lines in order to reflect the inter state price differentials. For the subsequent years, the State specific rural poverty lines in 1973-74 are updated by using state specific Consumer Price Indices of Agricultural Labourers (CPI-AL). Similarly the urban poverty lines are updated by state specific Consumer Price Indices of Industrial Workers (CPI-IW). Based on the Expert Group methodology, the poverty lines in 2004-05 at all India level were calculated as Rs. 356.30 per capita per month for rural areas and Rs. 538.60 per capita per month for urban areas and estimated poverty ratio as 27.5% (30.17 crore persons). Tendulkar Committee There had been much discussion about whether the poverty lines underlying these official estimates need to be redefined. Recognizing the need to address these issues, the Planning Commission in December, 2005 appointed an Expert Group under the Chairmanship of Prof. Suresh D. Tendulkar to review alternate concepts of poverty and to recommend changes in the existing procedures used for official estimates of poverty. The Tendulkar Committee submitted its report in December, 2009. The Committee has recommended that the rural poverty line should be recomputed to reflect money value in rural areas of the same basket of consumption that is associated with the existing urban poverty line. The resulting estimate of the all-India rural poverty head count ratio for 2004-05 was placed at 41.8 percent, urban poverty head count ratio at 25.7 percent and at all-India level at 37.2 percent. Arjun Sengupta Report The National Commission for Enterprises in the Unorganised Sector (NCEUS) set up by Ministry of Micro, Small and Medium Enterprises (MSME) in 2004 brought out a report on Conditions on Work and Promotion of Livelihoods in the Unorganised Sector. In this report, it was reported that 77% of the population had a per capita daily consumption of up to Rs. 20 in 2004-05. The Committee did not provide any justification for using the cut-off amount of Rs. 20 per day. Besides, the estimation of 77% is also erroneous since the percentage works out to 60.5 percent. This fact has also been reported in the Economic Survey 2008-09. Poverty Estimate by the World Bank In the World Development Indicators 2008 brought out by the World Bank, the global poverty line has been calibrated at US $ 1.25 a day. For India, the percentage of people living below the global poverty line as defined by World Bank has declined from 59.8% in 1981 to 51.3% in 1990 and further to 41.6% in 2005. Saxena Committee Report The Ministry of Rural Development constituted an Expert Group headed by Dr. N.C. Saxena to recommend a suitable methodology for identification of BPL families in rural areas. The Expert Group submitted its report in August 2009 and recommended to do away from the methodology of score based ranking of rural households followed for BPL census 2002. The Committee has recommended the criteria of automatic exclusion and automatic inclusion of certain sections of society facing deprivations and vulnerability, and that for rest of the people a survey be conducted to rank them on scale of 10 points. The Saxena Committee had also suggested that the national level poverty ratio can be assumed at 50 percent. This is not based on any specific justification. Latest Position The Mid Term Appraisal of the Eleventh Five Year Plan has indicated that the revised poverty lines for 2004-05 as recommended by the Tendulkar Committee have been accepted by the Planning Commission. These estimates put 41.8% of rural population and 25.7% of urban population as BPL, resulting in a national poverty head count ratio of 37.2%. As the poverty estimates of Planning Commission will continue to be based on the sample survey of consumption expenditure of households to be carried out by the National Sample Survey Organization (NSSO) after an interval of every five years, the next poverty estimates based on the Tendulkar Methodology will be available when the data of 66th Round of NSSO Survey for 2009-10 becomes available in end 2011. The Planning Commission is not aware of separate poverty estimates brought out by any State Government.